Injection pen



FIG. 1 is a perspective view the injection pen;

FIG. 2 is a side plan view thereof;

FIG. 3 is another side plan view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a front plan view thereof; and,

FIG. 7 is a rear plan view thereof.

The broken-line disclosure shown in the drawings is understood to be for illustrative purposes only, and forms no part of the claimed design. 

CLAIM The ornamental design for an injection pen, as shown and described. 